Technical Field
The present invention relates to a method and apparatus for manufacturing electronic devices.
Description of the Prior Art
In a conventional manufacturing process of electronic devices, a plurality of conductive bumps are typically used for attaching the electronic devices to a substrate, and a capillary underfill is applied to one or more sides of the electronic devices, enabling the underfill to creep along the gaps between the electronic devices and the substrate so as to fill these gaps. Typically, many small bubbles may exist in such underfill. Also, as shown in FIG. 3D, the underfill will creep along one or more sides of the electronic devices during the filling of the gaps. When a front edge of the underfill proceeds, an unfilled space may be formed at where the front edge meets another front edge due to various reasons, and this is referred to as “back pack phenomenon”. Specifically, as the front edges of the underfill proceed from sides of the electronic devices toward the center thereof meet each other, the back pack phenomenon occurs, and bubbles are formed (i.e., back pack spaces). The bubbles formed from the back pack phenomenon and the small bubbles in the underfill will eventually become voids in the underfill. These voids may cause the reliability of the electronic devices to drop and problems of electrical failure. Furthermore, in the case that the pitch between the conductive bumps is less than 100 micrometers (μm) and/or the gaps between the electronic devices and the substrate are less than 50 micrometers (μm), a capillary underfill is typically applied to one single side of the electronic device in order to prevent the back pack phenomenon. However, due to such small pitch and gaps, applying the capillary underfill to one single side of the electronic device may cause a slow filling rate. This may result in difficulties in controlling the creeping speed of the front edge of the underfill as well as the back pack phenomenon. As a result, such process needs to be abandoned, and other processes and materials of higher cost are alternatively chosen to protect the conductive bumps, which is definitely a significant obstacle to the development of electronic device miniaturization.
Accordingly, there is a need for a method and apparatus for manufacturing electronic devices, in which a capillary underfill is applicable to the case that the pitch between conductive bumps are less than 100 micrometers and/or the gaps between the electronic devices and the substrate are less than 50 micrometers, so as to promote the miniaturization of electronic devices.